A chemical vapor deposition (CVD) method is widely used as one process for forming a predetermined thin film on a substrate in creation of various semiconductor devices including LSI (large-scale integration) and of LCD (liquid crystal display).
Hydrogen atoms are widely used for the CVD method and also for terminals of dangling-bond in polysilicon, dry etching of crystalline silicon, cleaning of an evacuation enabled treatment chamber, and photoresist removal. In these methods, hydrogen atoms play an important part as an effective etching seed.
However, since hydrogen atoms contact with an internal wall of a treatment chamber in a vacuum treatment apparatus so as to be recombined and returned to hydrogen molecules, even if the hydrogen atoms are generated efficiently, it is difficult to maintain the density of the hydrogen atoms and transport them to a target position.
For example, it is reported that the extinction probability of hydrogen atoms on a surface of stainless steel is 0.20, and 90% of the hydrogen atoms are extinct the hydrogen atoms collide with the surface of the stainless steel ten times (non-patent document 1).
In a vacuum treatment apparatus which forms a thin film and modifies the property of the formed thin film in an evacuated treatment chamber, even if hydrogen atoms are tried to be used for the aforementioned various applications, the density of the hydrogen atoms is greatly attenuated, and thus it is difficult to provide the hydrogen atoms to practical uses.
Conventionally, it is proposed that a water cooling glass chamber is used as the treatment chamber in the vacuum treatment apparatus, and thus recombining and returning of hydrogen atoms into hydrogen molecules can be inhibited. However, even if this method is used, when the temperature of the internal wall of the chamber rises due to heat emission from a structure for heating a substrate arranged in the treatment chamber of the vacuum treatment apparatus, the recombining process is accelerated, and the attenuation of the hydrogen atom density proceeds (non-patent document 2). In the case where a certain heat source is present in the treatment chamber in order to heat a substrate, the hydrogen atom density is more likely to be attenuated.
On the other hand, it is known that hydrogen atoms can be generated efficiently by decomposition of hydrogen molecules on the surface of a high-temperature metallic catalyst (non-patent document 3).
As the vacuum treatment apparatus, therefore, a raw material gas supply system for supplying a raw material gas into a water cooling glass chamber and a heat generator (metallic catalyst) which is arranged in the water cooling glass chamber and is heated to a high temperature upon supply of an electric power from an electric power supply mechanism are provided. A hydrogen gas introduced from the raw material gas supply system into the water cooling chamber is decomposed by a heat generator maintained at high temperature so that hydrogen atoms are generated efficiently and are used for the various applications.
However, even if the water cooling glass chamber is used in order to inhibit the attenuation of the hydrogen atom density, since the glass chamber naturally requires mechanical strength (for example, a pressure due to a pressure difference between vacuum and air, water pressure of cooling water), it requires a certain thickness. Glass is known as a material whose heat conductivity is low, and when it has a certain thickness in order to satisfy the above mechanical strength, in the case where hydrogen atoms are generated by a high-temperature heat generator (metallic catalyst), for example, the temperature of the surface of the chamber internal wall inevitably rises even if the chamber is cooled by water. When the temperature of the chamber internal wall rises in such a manner, the recombining process is accelerated, and the attenuation of the hydrogen atom density proceeds. For this reason, even if hydrogen molecules are decomposed on the surface of the high-temperature metallic catalyst and hydrogen atoms are generated efficiently, it is difficult to provide the hydrogen atoms to practical uses.
When the glass chamber is used as the evacuation enabled treatment chamber in the vacuum treatment apparatus for forming a thin film, modifying the property of a formed thin film, removing photoresist and cleaning, this has great technical difficulty that a substrate size should be enlarged.    Non-patent document 1: P. Kae-Nune, J. Perrin, J. Jolly, and J. Guillon, Surf. Sci. 360, L495 (1996)    Non-patent document 2: J. Phys. vol. D27, page 1412 (1994)    Non-patent document 3: J. Appl. Phys. vol. 91, No. 3, page 1650 (2002)